1. Field of the Invention
The embodiments discussed herein are related to a magnetic noise rejection apparatus which eliminates magnetic noise with use of coils arranged near a target object, and a magnetic field measurement apparatus using the magnetic noise rejection apparatus.
2. Description of the Related Art
In the measurement of a faint magnetic field, a method has conventionally been employed in which an object to be measured is put in a magnetic shield chamber enclosed by a material having a large magnetic permeability such as permalloy, and an external magnetic field is prevented from entering the magnetic shield chamber.
Also, as another method of preventing the entrance of the external magnetic field, active magnetic shielding is available in which an external magnetic field entering from the outside is detected by a sensor, and the external magnetic field is canceled out by driving magnetic field cancellation coils provided around a measurement chamber. The related techniques are described in, for example, Japanese Laid-open Patent Publication Nos. 2012-095939, 2003-167038, and 2003-149311, and Japanese Patent Translation Publication No. 2015-525596.